5 V TTL TO 12 V CMOS Converter

In this pulse multiplier circuit, I need to return the voltage levels back to the 12 V standards that the engine management system expects, and therefore I am using this chip to convert from 5 V TTL level to 12 V level.

The MC14504B is a hex non-inverting level shifting IC based on CMOS technology. It will shift TTL signals to any CMOS logic level, determined by the supply voltage between 5 V and 15 V. Therefore, this is an ideal chip if you want to convert logic voltage levels from high voltage to low voltage, and vice versa. In this IC, the Vcc sets the input signal levels while Vdd selects the output voltage levels, hence it is possible to up-level and down-level translate logic voltages. It is also an excellent IC if you need to set the threshold levels precisely.

5 V to 12 V Logic Level Circuit

In this circuit, the input mode is set to TTL by connecting pin 13 to pin 1, hence the input signal at pin 9 is expected to be a TTL signal with a 5 V peak. In addition, setting Vcc to +5 V sets the input threshold to +5 V, and setting Vdd to +12 V sets the output signal at pin 10 to 12 V peak.

I decided to use this solution for voltage translation partly for safety and simplicity and making sure that the signals were according to recognised industrial standards for interfacing.

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